Comparative study of soils from several Romanian South-East regions and their influence on DNA degradation in tooth samples, from different periods of time

The degradation process of tooth and bone tissues and also of the DNA from them is a very complex one, determined by many concurrent factors which can be classified in three main categories – biological, physical and chemical factors. This paper presents our research regarding morphological aspects of soils and the influence of chemical composition on DNA degradation through fossilization process. In order to achieve our goals, we collected 27 soil samples from different archaeological sites, from various depths and different archeologically periods of time – Neolithic, The Bronze Age, The First Iron Age, The Romano-Byzantine Age, VIII-X century. We performed pH determination, calcination losses, SEM/EDS analysis of soil samples and we correlated our results with the DNA degradation index obtained from fossilized tooth samples collected from the same locations as soils. The results obtained from this analysis represent a small part of our efforts in reaching out the main objectives: a) establishing the identification and differentiation criteria for forensic soils; b) establishing which types of soil better preserves the human DNA from teeth and bones for further genetic analyses.